Hi,
Yes, the G74Sx and G46VW, G55VW, G75VW all use the same size plug as well as voltage, so you could use this larger wattage ASUS 180w adapter if you prefer.
Looks like that reseller listed it as 65w adapter under the specs as a mistake since 19v*9.47A = 180w, but if necessary, you may want to confirm with the reseller which one you are really getting.
Otherwise, the G74Sx 150w adapter is listed on the U.S. and Canadian eStore site as well as the G75VW 180w adapter if you still prefer to get it.
http://us.estore.asus.com/index.php?l=product_detail&p=720Hope this helps!